I need a high accuracy load cell

Hi. I need help in building a project. This involves measuring the density of objects using the Archimedes law. I need a high accuracy load cell.
0.001 or 0.005 grams accuracy
Also, can Arduino help this project run?

The sample of this device is in the link below

Look for one that has an RS232 interface, like this one: Laboratory PCE-LSM Series ← it has a density add-on kit

You will need something like the MAX232 chip to interface the Arduino with the scale.

Start with a scale that has some kind of digital output. Finding one that can do 1-5 mg resolution should be easy, but you have to take care with the installation of such sensitive scales. They're typically placed on special tables, with a heavy stone that in turn is placed on rubber patches to dampen vibrations.